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Build the Annual Cost and Cash Budget Separately

A yearly car number is useful only when it answers a specific question. Economic cost measures what ownership consumes. Cash outflow measures what leaves the bank account this year. Mixing them can double-count loan principal or hide the down payment.

1) Worked annual snapshot

This example is illustrative. The car costs S$130,000 and is expected to be worth S$40,000 after five years. The S$78,000 loan runs for five years at a 2.5% flat rate, matching the financing example used in the related guide.

The two totals do not need to match. The cost column recognises depreciation and interest. The cash column uses the full instalment, including principal. It excludes the down payment because that belongs in the purchase-year schedule.

2) Build each line from evidence

1. Depreciation: purchase price less realistic exit proceeds, divided by the planned holding period. Do not use dealer “annual depreciation” without checking the assumed exit value.
2. Interest: use the total borrowing cost from the written loan quote. Do not use the full instalment in the cost column.
3. Road tax: retrieve the actual payable amount from OneMotoring. Engine capacity, motor power, fuel type and vehicle age can change it.
4. Insurance: use the accepted policy quote, including GST, named drivers, excess and optional cover.
5. Fuel or charging: distance × energy consumption × price. Keep price and usage assumptions visible.
6. Parking and ERP: model the actual weekly route. These are usage costs, not universal flat amounts.
7. Maintenance: separate scheduled work from tyres, batteries, wear items and a repair reserve.

3) Add the cash events the annual average hides

An average monthly number smooths the year. Your bank account does not. Create a second calendar for:

• down payment and purchase fees;
• insurance and road-tax renewal months;
• scheduled services and expected wear-item replacements;
• a repair reserve that remains liquid until used; and
• the settlement amount and sale proceeds in the exit year.

If S$1,500 is transferred into a repair account and only S$400 is spent, the cash allocation is S$1,500 but the repair expense is S$400. The remaining S$1,100 is still household cash.

4) Compare the car with the service you would actually replace

Do not compare a full-availability car with today’s occasional ride-hailing bill and call the difference waste. Build the alternative route first: work trips, school or care trips, weekend travel, rentals for longer journeys and the cost of peak-hour failures. Then compare:

• incremental money: annual car cost minus the realistic alternative;
• usage: kilometres and trips actually served;
• liquidity: upfront cash and repair reserve tied up; and
• exit risk: debt outstanding versus likely sale proceeds.

Use the car versus ride-hailing calculator after replacing its defaults with your route.

5) Stress the household, not the average

A car can have an acceptable annual average and still fail every one of these tests.

FAQ

How should I calculate the yearly cost of owning a car?

For economic cost, add depreciation, financing interest and running expenses. For cash flow, use actual loan payments and running expenses, then separately schedule the down payment and other one-off cash.

Should I add depreciation and the full loan instalment?

No. That double-counts loan principal. Use depreciation plus interest for economic cost, or full repayments for cash-flow planning.

Is a repair reserve an expense?

A transfer into a reserve is a cash allocation, not an expense until the money is spent. Keep it visible in the cash budget without treating every unspent dollar as ownership cost.

Why can annual cost differ from annual cash outflow?

Depreciation measures value consumed, while repayments include principal that reduces debt. Upfront payments and sale proceeds also occur in different years.

Last updated: 21 Sep 2026 · Editorial Policy · Advertising Disclosure · Corrections